PROJECT SUMMARY The proposed project will examine emotional functioning in adolescents and young adults who are at heightened risk for imminently developing a psychotic disorder (i.e., ultra-high-risk [UHR] youth), focusing on interactions with their parental caregivers. While alterations in emotional functioning have been observed in individuals with psychosis and in UHR youth, the field has primarily focused on corroborative, self-report, and clinical interview-based measures, and as a result, currently has a limited understanding of how in-depth, dynamic interactions may play a pathogenic role. The current proposal is notable in linking across multiple modalities during experimental laboratory-based dyadic interactions to understand how emotional functioning in both UHR youth and caregivers predicts symptoms, social functioning, and clinical course over time. The first aim of the proposed research is to determine differences in emotional functioning during interaction between UHR-youth and caregivers compared to control youth and caregivers. This is of particular importance given that there are well-documented alterations in socioemotional functioning in UHR youth. Yet these alterations have rarely been examined in social contexts of key emotional significance, such as during interactions with their parental caregivers. Moreover, no studies have aimed to differentiate patterns of abnormality from developmentally normative emotional functioning during conflict interactions. The second aim is to determine which contexts reveal physiological vulnerability in UHR youth compared to control youth. Alterations in resting state autonomic physiology are a well-documented vulnerability factor in psychopathology, but have rarely been examined during negative (which put unique demands on the autonomic nervous system), neutral, and positive youth-caregiver interactions. The third aim is to evaluate whether emotional functioning during interactions in youth and caregivers predicts youth's symptoms and broader real-life social functioning concurrently and prospectively (over a period of 12 months). There is a large literature implicating caregivers' expressed emotions (EE) in psychosis, but no research has assessed emotional functioning in both youth and caregivers simultaneously during interaction. By delineating specific emotional qualities of UHR youth-caregiver interactions and identifying specific aspects of emotional functioning in both UHR youth as well as caregivers that put UHR youth further at risk, the proposed project will provide the foundation for identifying specific treatment targets for larger studies with both youth and caregivers.